For nearly three decades, black Americans had one source of reliable information about roadside businesses open to them, dubbed "The Green Book." In 1949, publisher Victor Green wrote about how he hoped his guide would become unnecessary one day.

On Martin Luther King Jr.'s birthday, it's worth remembering how driving was once an ordeal for a large number of Americans. Just as Jewish travelers once had guides to hotels and restaurants that would serve them when they traveled far from home, "The Negro Motorist's Green Book" offered to do the same for a growing numbers of African-Americans from the Great Depression onward whom could afford cars and wanted to escape the Jim Crow rules prevalent in mass transit.

Launched in 1936 as an annual booklet for the New York area, by 1949 the guide was the only national publication of its kind. In addition to the 50-state listings, it covered Mexico and the Bahamas, included listings for tailors and beauty parlors and even provided encouragement from Mark Twain: "Travel is fatal to prejudice." Supported in part by advertising from the businesses it highlighted, only two large corporations put their name in the '49 edition: Esso Oil and Ford.

Looking back, Green's book offers a reminder of how race warped the freedom that driving made possible. Black motorists in those eras frequently kept extra fuel, food and portable toilets on hand to avoid stopping in unfriendly locations. Even outside the South, roadside motels and diners often wouldn't serve black customers. As for the Deep South itself, the Green Book spoke warnings by omission; the '49 edition lists no restaurants available in all of Alabama.

In his introductions, Green offered his reasons for publishing the guide, and his hopes for closing the business:

There will be a day sometime in the near future when this guide will not have to be published. That is when we as a race will have equal opportunities and privileges in the United States. It will be a great day for us to suspend this publication for then we can go wherever we please, and without embarrassment. But until that time comes we shall continue to publish this information for your convenience each year.

With the passage of the Civil Rights Act of 1964 and the struggle led by King, Green stopped publishing his guide. You can see a PDF of the entire 1949 guide courtesy of The Henry Ford museum here.